1 files changed, 303 insertions, 0 deletions
diff --git a/src/expr.c b/src/expr.c
new file mode 100644
index 0000000..b4581f1
--- /dev/null
+++ b/src/expr.c
@@ -0,0 +1,303 @@
+/*
+ * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This code has been sponsored by Sophos Astaro <http://www.sophos.com>
+ */
+#include "internal.h"
+
+#include <time.h>
+#include <endian.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <netinet/in.h>
+
+#include <libmnl/libmnl.h>
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nf_tables.h>
+
+#include <libnftnl/expr.h>
+
+EXPORT_SYMBOL(nftnl_expr_alloc);
+struct nftnl_expr *nftnl_expr_alloc(const char *name)
+{
+	struct nftnl_expr *expr;
+	struct expr_ops *ops;
+
+	ops = nftnl_expr_ops_lookup(name);
+	if (ops == NULL)
+		return NULL;
+
+	expr = calloc(1, sizeof(struct nftnl_expr) + ops->alloc_len);
+	if (expr == NULL)
+		return NULL;
+
+	/* Manually set expression name attribute */
+	expr->flags |= (1 << NFTNL_EXPR_NAME);
+	expr->ops = ops;
+
+	if (ops->init)
+		ops->init(expr);
+
+	return expr;
+}
+
+EXPORT_SYMBOL(nftnl_expr_free);
+void nftnl_expr_free(const struct nftnl_expr *expr)
+{
+	if (expr->ops->free)
+		expr->ops->free(expr);
+
+	xfree(expr);
+}
+
+EXPORT_SYMBOL(nftnl_expr_is_set);
+bool nftnl_expr_is_set(const struct nftnl_expr *expr, uint16_t type)
+{
+	return expr->flags & (1 << type);
+}
+
+EXPORT_SYMBOL(nftnl_expr_set);
+int nftnl_expr_set(struct nftnl_expr *expr, uint16_t type,
+		   const void *data, uint32_t data_len)
+{
+	switch(type) {
+	case NFTNL_EXPR_NAME:	/* cannot be modified */
+		return 0;
+	default:
+		if (expr->ops->set(expr, type, data, data_len) < 0)
+			return -1;
+	}
+	expr->flags |= (1 << type);
+	return 0;
+}
+
+EXPORT_SYMBOL(nftnl_expr_set_u8);
+void
+nftnl_expr_set_u8(struct nftnl_expr *expr, uint16_t type, uint8_t data)
+{
+	nftnl_expr_set(expr, type, &data, sizeof(uint8_t));
+}
+
+EXPORT_SYMBOL(nftnl_expr_set_u16);
+void
+nftnl_expr_set_u16(struct nftnl_expr *expr, uint16_t type, uint16_t data)
+{
+	nftnl_expr_set(expr, type, &data, sizeof(uint16_t));
+}
+
+EXPORT_SYMBOL(nftnl_expr_set_u32);
+void
+nftnl_expr_set_u32(struct nftnl_expr *expr, uint16_t type, uint32_t data)
+{
+	nftnl_expr_set(expr, type, &data, sizeof(uint32_t));
+}
+
+EXPORT_SYMBOL(nftnl_expr_set_u64);
+void
+nftnl_expr_set_u64(struct nftnl_expr *expr, uint16_t type, uint64_t data)
+{
+	nftnl_expr_set(expr, type, &data, sizeof(uint64_t));
+}
+
+EXPORT_SYMBOL(nftnl_expr_set_str);
+int nftnl_expr_set_str(struct nftnl_expr *expr, uint16_t type, const char *str)
+{
+	return nftnl_expr_set(expr, type, str, strlen(str) + 1);
+}
+
+EXPORT_SYMBOL(nftnl_expr_get);
+const void *nftnl_expr_get(const struct nftnl_expr *expr,
+			      uint16_t type, uint32_t *data_len)
+{
+	const void *ret;
+
+	if (!(expr->flags & (1 << type)))
+		return NULL;
+
+	switch(type) {
+	case NFTNL_EXPR_NAME:
+		*data_len = strlen(expr->ops->name) + 1;
+		ret = expr->ops->name;
+		break;
+	default:
+		ret = expr->ops->get(expr, type, data_len);
+		break;
+	}
+
+	return ret;
+}
+
+EXPORT_SYMBOL(nftnl_expr_get_u8);
+uint8_t nftnl_expr_get_u8(const struct nftnl_expr *expr, uint16_t type)
+{
+	const void *data;
+	uint32_t data_len;
+
+	data = nftnl_expr_get(expr, type, &data_len);
+	if (data == NULL)
+		return 0;
+
+	if (data_len != sizeof(uint8_t))
+		return 0;
+
+	return *((uint8_t *)data);
+}
+
+EXPORT_SYMBOL(nftnl_expr_get_u16);
+uint16_t nftnl_expr_get_u16(const struct nftnl_expr *expr, uint16_t type)
+{
+	const void *data;
+	uint32_t data_len;
+
+	data = nftnl_expr_get(expr, type, &data_len);
+	if (data == NULL)
+		return 0;
+
+	if (data_len != sizeof(uint16_t))
+		return 0;
+
+	return *((uint16_t *)data);
+}
+
+EXPORT_SYMBOL(nftnl_expr_get_u32);
+uint32_t nftnl_expr_get_u32(const struct nftnl_expr *expr, uint16_t type)
+{
+	const void *data;
+	uint32_t data_len;
+
+	data = nftnl_expr_get(expr, type, &data_len);
+	if (data == NULL)
+		return 0;
+
+	if (data_len != sizeof(uint32_t))
+		return 0;
+
+	return *((uint32_t *)data);
+}
+
+EXPORT_SYMBOL(nftnl_expr_get_u64);
+uint64_t nftnl_expr_get_u64(const struct nftnl_expr *expr, uint16_t type)
+{
+	const void *data;
+	uint32_t data_len;
+
+	data = nftnl_expr_get(expr, type, &data_len);
+	if (data == NULL)
+		return 0;
+
+	if (data_len != sizeof(uint64_t))
+		return 0;
+
+	return *((uint64_t *)data);
+}
+
+EXPORT_SYMBOL(nftnl_expr_get_str);
+const char *nftnl_expr_get_str(const struct nftnl_expr *expr, uint16_t type)
+{
+	uint32_t data_len;
+
+	return (const char *)nftnl_expr_get(expr, type, &data_len);
+}
+
+EXPORT_SYMBOL(nftnl_expr_build_payload);
+void nftnl_expr_build_payload(struct nlmsghdr *nlh, struct nftnl_expr *expr)
+{
+	struct nlattr *nest;
+
+	mnl_attr_put_strz(nlh, NFTA_EXPR_NAME, expr->ops->name);
+
+	if (!expr->ops->build)
+		return;
+
+	nest = mnl_attr_nest_start(nlh, NFTA_EXPR_DATA);
+	expr->ops->build(nlh, expr);
+	mnl_attr_nest_end(nlh, nest);
+}
+
+static int nftnl_rule_parse_expr_cb(const struct nlattr *attr, void *data)
+{
+	const struct nlattr **tb = data;
+	int type = mnl_attr_get_type(attr);
+
+	if (mnl_attr_type_valid(attr, NFTA_EXPR_MAX) < 0)
+		return MNL_CB_OK;
+
+	switch (type) {
+	case NFTA_EXPR_NAME:
+		if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0)
+			abi_breakage();
+		break;
+	case NFTA_EXPR_DATA:
+		if (mnl_attr_validate(attr, MNL_TYPE_NESTED) < 0)
+			abi_breakage();
+		break;
+	}
+
+	tb[type] = attr;
+	return MNL_CB_OK;
+}
+
+struct nftnl_expr *nftnl_expr_parse(struct nlattr *attr)
+{
+	struct nlattr *tb[NFTA_EXPR_MAX+1] = {};
+	struct nftnl_expr *expr;
+
+	if (mnl_attr_parse_nested(attr, nftnl_rule_parse_expr_cb, tb) < 0)
+		goto err1;
+
+	expr = nftnl_expr_alloc(mnl_attr_get_str(tb[NFTA_EXPR_NAME]));
+	if (expr == NULL)
+		goto err1;
+
+	if (tb[NFTA_EXPR_DATA] &&
+	    expr->ops->parse &&
+	    expr->ops->parse(expr, tb[NFTA_EXPR_DATA]) < 0)
+		goto err2;
+
+	return expr;
+
+err2:
+	xfree(expr);
+err1:
+	return NULL;
+}
+
+EXPORT_SYMBOL(nftnl_expr_snprintf);
+int nftnl_expr_snprintf(char *buf, size_t remain, const struct nftnl_expr *expr,
+			uint32_t type, uint32_t flags)
+{
+	int ret;
+	unsigned int offset = 0;
+
+	if (remain)
+		buf[0] = '\0';
+
+	if (!expr->ops->output || type != NFTNL_OUTPUT_DEFAULT)
+		return 0;
+
+	ret = expr->ops->output(buf + offset, remain, flags, expr);
+	SNPRINTF_BUFFER_SIZE(ret, remain, offset);
+
+	return offset;
+}
+
+static int nftnl_expr_do_snprintf(char *buf, size_t size, const void *e,
+				  uint32_t cmd, uint32_t type, uint32_t flags)
+{
+	return nftnl_expr_snprintf(buf, size, e, type, flags);
+}
+
+EXPORT_SYMBOL(nftnl_expr_fprintf);
+int nftnl_expr_fprintf(FILE *fp, const struct nftnl_expr *expr, uint32_t type,
+		       uint32_t flags)
+{
+	return nftnl_fprintf(fp, expr, NFTNL_CMD_UNSPEC, type, flags,
+			     nftnl_expr_do_snprintf);
+}